1. Field of the Invention
This invention relates to a dye imbibition imaging element comprising a photosensitive polyesterionomer for forming a positive, continuous tone, dye image. It also relates to a process for forming such a dye image by means of water rinsing the imaging element after imagewise exposure and imbibing an anionic dye into the element.
2. State of the Art
Photohardenable imaging compositions and elements useful in preparing continuous tone dye images, such as for color proofing, are known. These are described in, for example, Research Disclosure, May 1978, Item No. 16976, and U.S. Pat. No. 4,220,700. The known compositions and elements involve a wash-off light-sensitive composition comprising, in admixture, as a photohardenable material, a light-sensitive diazo resin and a mordant for an anionic dye. Such a composition is useful for forming a dye image by imagewise exposing the composition as a layer on a suitable support, then developing the layer by means of water by rinsing, followed by imbibing an anionic dye into the layer in which it is immobilized by the mordant. The dye image is capable of being transferred to a receiver layer comprising a cationic mordant of greater mordanting strength than the mordant mixed with the light-sensitive diazo resin. While such photohardenable imaging compositions and elements are useful for forming negative dye images, a need has existed for a suitable photohardenable, dye imbibition imaging element for producing a positive, continuous tone, dye image.
The photohardenable imaging materials designed to produce high contrast images, such as by means of a photoresist, are not useful for forming continuous tone, dye images. In this regard, uncharged photopolymers, such as poly[1,4-cyclohexylenebis(oxyethylene) succinate-co-p-phenylenebis(acrylate)] (45:55), provide higher contrast images than are desired for positive, continuous tone, dye images. This is illustrated in the following comparative examples.